Aiming　at　the　voltage　sag　caused　by　power　system　fault　affects　the　system　many　times　through　electricity-gas　coupling　equipment,　a　location　and　constant　volume　method　of　gas　storage　device　in　integrated　electricity-gas　energy　system　for　mitigating　voltage　sag　effect　is　proposed.　The　impacts　of　voltage　sags　in　power　system　on　the　integrated　electricity-gas　energy　system　are　analyzed.　Then,　the　location　method　of　gas　storage　device　in　natural　gas　system　is　proposed　based　on　the　sensitivity　analysis.　Furthermore,　with　the　comprehensive　consideration　of　investment　cost　and　benefit,　the　best　configuration　scheme　of　gas　storage　device　is　determined　by　taking　the　maximum　benefit　after　installing　gas　storage　device　as　the　objective　function.　The　correctness　and　effectiveness　of　the　mitigation　method　are　verified　by　analyzing　an　example　of　the　integrated　electricity-gas　energy　system　composed　of　IEEE　14-bus　power　system　and　11-node　natural　gas　system.　©　2022,　Electric　Power　Automation　Equipment　Press.　All　right　reserved.